<?xml version="1.0" encoding="utf-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Drag and drop: dropping block element onto canvas</title>
<style type="text/css">
div
  {width:20px;
  height:20px;
  background-color:green;}
</style>
<script type="application/ecmascript">
function paint(color)
  {var canvas = document.querySelector('canvas'),
  c = canvas.getContext('2d');
  c.fillStyle = color;
  c.beginPath();
  c.moveTo(0,0);
  c.lineTo(100,0);
  c.lineTo(100,100);
  c.lineTo(0,100);
  c.closePath();
  c.fill();}
function start(event)
  {event.dataTransfer.effectAllowed = 'copy';
  event.dataTransfer.setData('text/plain', 'green');}
</script>
</head>
<body onload="paint('gray')">
<div draggable="true" ondragstart="start(event)"/>
<p>Drag green box above to the gray canvas below. Canvas should turn green when you drop green box on it.</p>
<p>
  <canvas width="100" height="100" ondragenter="event.preventDefault()" ondragover="return false" ondrop="paint(event.dataTransfer.getData('text/plain'))">Canvas</canvas>
</p>
</body>
</html>
